[Epidemiology of primary tumors of the pleura]

The authors briefly reviewed the literature concerning the risk factors for primary pleural tumors in humans. The results from the most relevant studies emphasize the fact that the large majority of mesotheliomas are associated with exposure to asbestos or asbestiform fibers. Exposure to asbestos is mainly through industrial use, and mesotheliomas result from occupational, para-occupational, or environmental exposure. Fibers of crocidolite, amosite, and chrysotile appear to be, in descending order, more carcinogenic for pleural tissues. The authors summarize the available data on consumption of asbestos and asbestos-based products in Italy. The chrysotile-asbestos mine in Balangero (Piedmont) stimulated the industrial production of asbestos-cement; asbestos has been largely sprayed among shipyards and user for insulating railroad coaches and carriages. Italy had the greatest consumption of crocidolite in Europe, which was not banned until 1986. The authors discuss the major findings derived from descriptive epidemiological data presented in previous papers dealing with this issue. In addition, standardized mortality rates of primary pleural tumors for European countries are shown. A clearly increasing trend for mortality is observed in Italy, which has also the provinces with the highest mortality rates in Europe. Among Italian provinces, the mortality rates are consistent with the number of asbestosis cases receiving workman's compensation. The authors present the results of both cohort and case-control analytical studies performed in Italy, and provide suggestions for further research.